Eeschema: fix sheet minimum size bug.

Convert minimum sheet width and height definitions from mils to internal
units.

Add comment to sheet minimum width and height definitions to indicate
sizes are in mils.

demos/complex_hierarchy/complex_hierarchy.pro

@@ -1,4 +1,4 @@
-update=01/01/2020 17:37:30
+update=Tue 21 Jan 2020 12:19:00 PM EST
 version=1
 last_client=kicad
 [cvpcb]
@@ -254,3 +254,19 @@ uViaDrill=0.2032
 dPairWidth=0.4
 dPairGap=0.35
 dPairViaGap=0.25
+[schematic_editor]
+version=1
+PageLayoutDescrFile=
+PlotDirectoryName=
+SubpartIdSeparator=0
+SubpartFirstId=65
+NetFmtName=Pcbnew
+SpiceAjustPassiveValues=0
+LabSize=50
+ERC_WriteFile=0
+ERC_TestSimilarLabels=1
+ERC_CheckUniqueGlobalLabels=1
+ERC_CheckBusDriverConflicts=1
+ERC_CheckBusEntryConflicts=1
+ERC_CheckBusToBusConflicts=1
+ERC_CheckBusToNetConflicts=1

eeschema/sch_sheet.cpp

@@ -50,7 +50,7 @@ SCH_SHEET::SCH_SHEET( const wxPoint& pos ) :
 {
     m_Layer = LAYER_SHEET;
     m_pos = pos;
-    m_size = wxSize( MIN_SHEET_WIDTH, MIN_SHEET_HEIGHT );
+    m_size = wxSize( Mils2iu( MIN_SHEET_WIDTH ), Mils2iu( MIN_SHEET_HEIGHT ) );
     SetTimeStamp( GetNewTimeStamp() );
     m_sheetNameSize = GetDefaultTextSize();
     m_fileNameSize = GetDefaultTextSize();
@@ -264,7 +264,7 @@ bool SCH_SHEET::HasUndefinedPins()
 
 int SCH_SHEET::GetMinWidth() const
 {
-    int width = MIN_SHEET_WIDTH;
+    int width = Mils2iu( MIN_SHEET_WIDTH );
 
     for( size_t i = 0; i < m_pins.size();  i++ )
     {
@@ -304,7 +304,7 @@ int SCH_SHEET::GetMinWidth() const
 
 int SCH_SHEET::GetMinHeight() const
 {
-    int height = MIN_SHEET_HEIGHT;
+    int height = Mils2iu( MIN_SHEET_HEIGHT );
 
     for( size_t i = 0; i < m_pins.size();  i++ )
     {

eeschema/sch_sheet.h

@@ -39,8 +39,8 @@ class SCH_EDIT_FRAME;
 class NETLIST_OBJECT_LIST;
 
 
-#define MIN_SHEET_WIDTH  500
-#define MIN_SHEET_HEIGHT 150
+#define MIN_SHEET_WIDTH  500    // Units are mils.
+#define MIN_SHEET_HEIGHT 150    // Units are mils.
 
 
 /**